BLBS102-c06 BLBS102-Simpson March 21, 2012 12:6 Trim: 276mm X 219mm Printer Name: Yet to Come
116 Part 2: Biotechnology and EzymologyTable 6.1.(Continued)6.3. Forming carbon-nitrogen bonds
6.3.1 Acid-ammonia (or amine) ligases (amide synthases)
6.3.2 Acid-amino-acid ligases (peptide synthases)
6.3.3 Cyclo-ligases
6.3.4 Other carbon-nitrogen ligases
6.3.5 Carbon-nitrogen ligases with glutamine as amido-N-donor
6.4. Forming carbon-carbon bonds
6.5. Forming phosphoric ester bonds
6.6. Forming nitrogen-metal bondsSources: Ref. NC-IUBMB. 1992. Enzyme Nomenclature, 6th ed. San Diego (CA): Academic Press, Inc. With permission. NC-IUBMB Enzyme
Nomenclature Website (www.iubmb.org).
aReaders should refer to the website: http://www.chem.qmul.ac.uk/iubmb/enzyme/rules.html for the most up-to-date changes.of the ICUMB (NC-IUBMB). The information is reformatted in
table form instead of text form for easier reading and compari-
son.
Table 6.2 shows the rules for systematic names and guide-
lines for common names as suggested by NC-IUBMB. Table 6.3
shows the rules and guidelines for particular classes of enzymes
as suggested by NC-IUBMB. The concept on reformatting used
in Table 6.1 is also applied.EXAMPLES OF COMMON FOOD
ENZYMESThe food industry likes to use terms more easily understood
by its people and is slow to adopt changes. For example, some
commonly used terms related to enzymes are very general terms
and do not follow the recommended guidelines established by
NC-IUBMB. Table 6.4 is a list of enzyme groups commonly
used by the food industry and researchers (Nagodawithana and
Reed 1993).Table 6.2.General Rules for Generating Systematic Names and Guidelines for Common NamesaRules and
Guidelines No. Descriptions- Common names: Generally accepted trivial names of substances may be used in enzyme names. The prefix
d-should be omitted for alld-sugars andl-for individual amino acids, unless ambiguity would be caused. In
general, it is not necessary to indicate positions of substitutes in common names, unless it is necessary to
prevent two different enzymes having the same name. The prefixketo-is no longer used for derivatives of
sugars in which -CHOH- has been replaced by –CO–; they are named throughout as dehydrosugars.
Systematic names: To produce usable systematic names, accepted names of substrates forming part of the
enzyme names should be used. Where no accepted and convenient trivial names exist, the official IUPAC
rules of nomenclature should be applied to the substrate name. The 1, 2, 3 system of locating substitutes
should be used instead of theαβγsystem, although group names such asβ-aspartyl-,γ-glutamyl- and also
β-alanine-lactone are permissible;αandβshould normally be used for indicating configuration, as in
α-d-glucose. For nucleotide groups, adenylyl (not adenyl), etc. should be the form used. The name oxo acids
(not keto acids) may be used as a class name, and for individual compounds in which –CH2– has been
replaced by –CO–, oxo should be used. - Where the substrate is normally in the form of an anion, its name should end in -aterather than -ic,e.g.,lactate
dehydrogenase, not “lactic acid dehydrogenase.” - Commonly used abbreviations for substrates, e.g., ATP, may be used in names of enzymes, but the use of new
abbreviations (not listed in recommendations of the IUPAC-IUB Commission on Biochemical
Nomenclature) should be discouraged. Chemical formulae should not normally be used instead of names of
substrates. Abbreviations for names of enzymes, e.g., GDH, should not be used. - Names of substrates composed of two nouns, such as glucose phosphate, which are normally written with a
space, should be hyphenated when they form part of the enzyme names, and thus become adjectives, e.g.,
glucose-6-phosphate dehydrogenase(EC 1.1.1.49). This follows standard practice in phrases where two
nouns qualify a third; see e.g.,Handbook of Chemical Society Authors, 2nd ed., p. 14 (The Chemical
Society, London, 1961).